Weekly Weather: Hot this week, followed by good rain chances this weekend

Good morning and welcome to my weekly weather report on the immediate past, present and future of weather in the Bayou City.

PAST

Now that we’ve passed the 5th anniversary of Hurricane Ike, let’s discuss the most significant weather event to hit Houston since then. I’m speaking, of course, of drought.

Every year since Ike hit the city of Houston has run a rainfall deficit, as shown in the graphics below (brown indicates a rain deficit, green a rainfall surplus), and in most years the drought was quite significant.

I’m often asked whether we’ve seen some sort of long-term pattern change that might indicate the Houston region can no longer expect to receive about 50 inches in annual rainfall. I don’t know the answer for certain, but I think it is no. What we have seen during the last five years is an extraordinary drought (2011) and a real lack of rainfall due to tropical systems, whether from depressions to hurricanes. This will eventually change.

Bottom line: Even if 2013 remains relatively dry, I’d still expect to see wetter years ahead.

Anyway, let’s do the numbers for last week.

Date

High Temp.

Low Temp.

Average

Departure

Rainfall

Monday

92

74

83

+1

0.00

Tuesday

90

74

82

+1

0.09

Wednesday

92

72

82

+1

0.00

Thursday

94

74

84

+3

0.00

Friday

96

73

85

+5

0.00

Saturday

94

74

84

+4

0.00

Sunday

91

74

83

+3

0.07

Average

92.7

73.6

83.3

+2.6

0.16 (tot.)

Here’s hoping the 96 degree temperature on Friday is the last 95+ degree day of the year.

PRESENT

This week’s weather will be warm for mid-September, with highs in the low- to mid-90s and overnight lows in the mid-70s.

There will be a battle this week between high pressure over the southern United States and tropical moisture moving into Texas from Hurricane Ingrid, which is approaching the Mexico coast today.

As much as 30 percent of the metro area could see rain today, say forecasters with the Houston/Galveston office of the National Weather Service, with rain most likely to the southwest of Houston. Rain chances will be highest this afternoon, when temperatures are warmest. All in all, however, I wouldn’t expect rain accumulations to be that significant.

These slight rain chances should hang around through Wednesday.

After that time the high pressure system should weaken a bit, opening the door to more significant moisture.

By Friday and Sunday forecast models are generally consistent in showing a strong flow of moisture at the surface of the Gulf into the Houston metro region, maxing out on Friday and Saturday. At this point this suggests rain chances will be good this weekend, perhaps giving Houston its best chance at significant rain for a couple of weeks.

European model rainfall accumulation forecast through Saturday night. Most of the rain is forecast on Friday and Saturday. (Weather Bell)

I’ll have a lot more confidence in the Friday and Saturday rains if the models remain consistent over the next couple of days in their forecasts. We need it, that’s for sure.

FUTURE

It’s the time of year when, historically, we can begin to look for our first strong cool front.

Alas, there’s no sign of such a robust front in the 10-day forecast from the European model nor the 16-day forecast from the GFS model. What does this mean? It means I wouldn’t expect a front before Sept. 25, and perhaps later than that.

Finally, if you want several daily updates on weather, please “like” my SciGuy Facebook page. It’s the best place for multiple daily updates on our weather, delivered right to your news feed.

FINE PRINT

As always, thank you to the fine professionals at the National Weather Service for the information and data that make this weekly blog entry possible. Also, bear in mind there’s always uncertainty in weather forecasting, particularly the timing and intensity of precipitation.

Is there a handy graphic for the average yearly precipitation for the entire U.S.? While it’s not good for us to be below average several years in a row, doesn’t our region get much higher averages than most of the country anyway? I know parts of California have only had 2 or 3 inches of rain this year. As bad as things are for us, we can get that total easily in one day.

That’s not really the point. California is a desert, and it gets its drinking water from snow melt. Our native plants require a certain amount of water to prevent our landscape looking like it does, and we need our lakes to be continually filled up as we flush them down the drain.

Not to step on the bleak, dreary outlook but what are levels of… Lakes and rivers!?!? That is more important!!!! Also, the recent floods in Colorado will eventually work their way into Texas and raise these levels. Water source for the masses is key. If our lawn and trees die then atleast we have a water source.

The Rio Grande is flooding in New Mexico and maybe the heavy rains from Ingrid in Mexico will also help for Amistad and Falcon reservoirs. The Austin lakes are still getting nothing unless we get heavy rains in Central Texas.

Much of the Colorado floodwater will drain into the Platte River and Arkansas River, heading on to the Mighty Mississippi. We need rain in Texas to help Texas.
If you want to see a result of less-than-normal rainfall, go take a peek at the dead trees in any pine forest. My place in East Texas has lost a significant percentage (maybe 20%) of formerly healthy pine growth. Now, those trees are falling over and creating a significant fire hazard.

“I’m often asked whether we’ve seen some sort of long-term pattern change that might indicate the Houston region can no longer expect to receive about 50 inches in annual rainfall. I don’t know the answer for certain, but I think it is no. What we have seen during the last five years is an extraordinary drought (2011) and a real lack of rainfall due to tropical systems, whether from depressions to hurricanes”

What I believe needs to be examined is “Why are ‘high-pressure-systems’ sitting on top of us in a stationary position so long?” That is the ques.

The SE US experienced horrible 4-6 yr droughts, but this yr 0 stationary high pressure systems. They were receiving 3-5″ per week for 8-9 weeks.

Whatever makes hi-pressure systems shift, intensify and remain fixed is what I would be studying, more so how to get their butts to move on we be even more significant.

I sure hope this weekend we receive A LOT of rain.

Thanks for the article and the graphs really put the drought into perspective.

Good, I was beginning to worry that you might report that a cool front might make it to the area before Thanksgiving. Would hate to ruin an otherwise perfect extended summer for all of those who look forward to the heat more than the cool!

Excellent job with the graphics, SciGuy. Might I make two suggestions? (1) If you could put the data underlying your graphics on some accessible site in some reasonable format it would enable others to piggyback on your work. (2) I’d love to see the 2009-2013 graphs all put together so one could see the cumulative deficit rather than the annual deficits. But great work both in prioritizing this issue and presenting the information in a good visual fashion.

Thanks for the great information and updates Eric. I’ve been a lurker on here since before Ike. Thought I would chime in now.

Rodger, it is interesting that after TxDOT and HCTRA decided that paving a concrete gateway to Katy and that the drought started. Memorial Park was a green paradise until 24 lanes of concrete created a heat sink on the western edge of downtown. Now with the 290 rebuild I wonder how much more heat we can generate. And let’s not forget the Grand Parkway boondoggle through the Katy prairie watershed. At least it will be easy for the folks in Katy to evacuate.

I think it’s a stretch to believe that the heating is from the concrete is causing a drought. If the concrete were heating the atmosphere, that would raise temperatures and cause more water to evaporate. Thus, causing more moisture in the air and eventually more rain.

More likely we’re seeing/feeling subtle shifts in the jet stream based on macro-global changes. We also have a very limited understanding of climate and the forces of changes. The planet is warming, no doubt. The causes and the impacts are not understood.

What I do know is that plenty of “rainy” places in the world used to be dry and plenty of dry places used to be rainy.

The drought is pretty much history in NM now. Lots of great rain and full reservoirs for a change. Of course, the hand wringers will never let up about what might happen next year, etc., but for now we are all happy with the precip.

To answer your question, No there won’t be any hurricanes to hit the Houston area this season,so don’t worry…..Secondly, “rain is most likely southwest of Houston” is spot on, since Brownsville is SW of Houston.

Eric,
In his daily update, Dr. Jeff Masters predicts that there a small probability of Cape Verde hurricane, but entertains a high possibility of several more storms in the Gulf….What is Your take on that, and, how likely, that they may affect Texas or Houston?
Thanks